Presently, as standards of the next-generation mobile communication systems, LTE (Long Term Evolution) is specified by 3GPP (the 3rd Generation Partnership Project) as described in 3GPP TS 36.211 “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation (Release 8)”, Jul. 10, 2007. As the LTE specification, the SC-FDMA (Single-Carrier Frequency Division Multiple Access) method is used by which the PAPR (Peak-to-Average Power Ratio) of transmitted signals is suppressed in uplinks (communications from user equipment to a base station) of an LTE system to enable reduction in the load of a transmission power amplifier and longer battery life of the user equipment. The SC-FDMA is a frequency-division-based method. In addition to the SC-FDMA, OFDM (Orthogonal Frequency Division Multiplexing), OFDMA (Orthogonal Frequency Division Multiple Access), and the like are frequency-division-based methods.